Buggy code:
public final class IndexSchema { static final Logger log = Logger . getLogger ( IndexSchema . class . getName ( ) ) ; private final String schemaFile ; private String name ; private float version ; public IndexSchema ( String schemaFile ) { } public InputStream getInputStream ( ) { } float getVersion ( ) { } public String getName ( ) { } private final HashMap < String , SchemaField > fields = new HashMap < String , SchemaField > ( ) ; private final HashMap < String , FieldType > fieldTypes = new HashMap < String , FieldType > ( ) ; private final List < SchemaField > fieldsWithDefaultValue = new ArrayList < SchemaField > ( ) ; public Map < String , SchemaField > getFields ( ) { } public Map < String , FieldType > getFieldTypes ( ) { } public List < SchemaField > getFieldsWithDefaultValue ( ) { } private Similarity similarity ; public Similarity getSimilarity ( ) { } private Analyzer analyzer ; public Analyzer getAnalyzer ( ) { } private Analyzer queryAnalyzer ; public Analyzer getQueryAnalyzer ( ) { } private String defaultSearchFieldName = null ; private String queryParserDefaultOperator = "OR" ; public SolrQueryParser getSolrQueryParser ( String defaultField ) { } public String getDefaultSearchFieldName ( ) { } public String getQueryParserDefaultOperator ( ) { } private SchemaField uniqueKeyField ; public SchemaField getUniqueKeyField ( ) { } private String uniqueKeyFieldName ; private FieldType uniqueKeyFieldType ; public Fieldable getUniqueKeyField ( Document doc ) { } public String printableUniqueKey ( Document doc ) { } private SchemaField getIndexedField ( String fname ) { } private class SolrIndexAnalyzer extends Analyzer { protected final HashMap < String , Analyzer > analyzers ; SolrIndexAnalyzer ( ) { } protected HashMap < String , Analyzer > analyzerCache ( ) { } protected Analyzer getAnalyzer ( String fieldName ) { } public TokenStream tokenStream ( String fieldName , Reader reader ) { } public int getPositionIncrementGap ( String fieldName ) { } } private class SolrQueryAnalyzer extends IndexSchema . SolrIndexAnalyzer { protected HashMap < String , Analyzer > analyzerCache ( ) { } protected Analyzer getAnalyzer ( String fieldName ) { } } private void readConfig ( ) { } private static Object [ ] append ( Object [ ] orig , Object item ) { } private Analyzer readAnalyzer ( Node node ) throws XPathExpressionException { } private TokenizerFactory readTokenizerFactory ( Node node ) { } private TokenFilterFactory readTokenFilterFactory ( Node node ) { } abstract static class DynamicReplacement implements Comparable < IndexSchema . DynamicReplacement > { static final int STARTS_WITH = 1 ; static final int ENDS_WITH = 2 ; final String regex ; final int type ; final String str ; protected DynamicReplacement ( String regex ) { } public boolean matches ( String name ) { } public int compareTo ( IndexSchema . DynamicReplacement other ) { } } static final class DynamicField extends IndexSchema . DynamicReplacement { final SchemaField prototype ; DynamicField ( SchemaField prototype ) { } SchemaField makeSchemaField ( String name ) { } public String toString ( ) { } } static final class DynamicCopy extends IndexSchema . DynamicReplacement { final SchemaField targetField ; DynamicCopy ( String regex , SchemaField targetField ) { } public String toString ( ) { } } private IndexSchema . DynamicField [ ] dynamicFields ; public boolean hasExplicitField ( String fieldName ) { } public SchemaField getFieldOrNull ( String fieldName ) { } public SchemaField getField ( String fieldName ) { SchemaField f = fields . get ( fieldName ) ; if ( f != null ) return f ; for ( IndexSchema . DynamicField df : dynamicFields ) { if ( df . matches ( fieldName ) ) return df . makeSchemaField ( fieldName ) ; } <START_BUG> throw new SolrException ( 1 , ( "undefined<seq2seq4repair_space>field<seq2seq4repair_space>" + fieldName ) ) ; <END_BUG> } public FieldType getFieldType ( String fieldName ) { } public FieldType getFieldTypeNoEx ( String fieldName ) { } public FieldType getDynamicFieldType ( String fieldName ) { } private FieldType dynFieldType ( String fieldName ) { } private final Map < String , SchemaField [ ] > copyFields = new HashMap < String , SchemaField [ ] > ( ) ; private IndexSchema . DynamicCopy [ ] dynamicCopyFields ; public SchemaField [ ] getCopyFields ( String sourceField ) { } private static boolean isWildCard ( String name ) { } }

Fix:
throw new SolrException ( 400 , ( "undefined<seq2seq4repair_space>field<seq2seq4repair_space>" + fieldName ) ) ;